Tim Mulvaney has an extensive post on the Supreme Court's decision to grant cert in the “exaction” takings case of Koontz v. St. John’s River Water Management District. The rub:

The Koontz case raises two important questions: (1) whether the Nollan/Dolan test applies to exactions beyond those that require public occupation of private lands; and (2) whether the Nollan/Dolan test is applicable at the point in time when an exaction is merely proposed. Drawing from several of my earlier posts on Koontz (available here and here), below I will attempt to provide a primer on the facts and the issues at stake.

The whole post is worth reading - Tim is an expert on exactions and breaks the case down in a very succinct and intelligible way.